SQL 2008 Filestream Error on Windows 2008 Datacenter

We have a Virtual Private Server running Windows 2008 Datacenter. We installed SQL Server 2008 R2 Enterprise and we are failing to enable SQL FILESTREAM .

1. When setting the FILESTREAM Option under SQL Configuration Manager we are getting the following error: >>"There was an unknown error applying the FILESTREAM settings. Check the parameters are valid".<<

2. We tried activating the FILESTREAM from the command line and got the following error: >>"Method failed: hr=-2147023621"<<

3. We tried re-installing SQL Server so that we activate FILESTREAM during installation but we are getting the following error and the installation will abort:  >>"This driver has been blocked from loading".<<


What could be the problem? Is it:
- A compatibility issue of Windows Datacenter?

- A compatibility issue with VPS environment?